bad throughput performance on multiple systems: Re: Fwd: Re: Disappointing packets-per-second performance results on a Dell,PE R530

Navdeep Parhar nparhar at gmail.com
Mon Mar 13 17:03:30 UTC 2017


On Sun, Mar 12, 2017 at 5:35 PM, John Jasen <jjasen at gmail.com> wrote:
>
> UDP traffic. dmesg reports 16 txq, 8 rxq -- which is the default for
> Chelsio.
>

I don't recall offhand, but UDP might be using 2-tuple hashing by
default and that might affect the distribution of flows across queues.
Are there senders generating IP fragments by any chance (that'll
depend on the "send size" that your UDP application is using)?

Have you tried limiting the adapter's rx ithreads to the CPU that the
PCIe slot with the adapter is wired to?

Regards,
Navdeep


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